Furnace door frame construction



J. THORNTON FURNACE DOOR FRAME CONSTRUCTION Sept. 12, 1939.

Filed Nov. 24, 1937 2 She etsSheet 1 JOHN 771oR/vro/v,

INVENTOR ATTORNEY5.

Sept. 12, 1939.

J. THORNTON I 2,172,995

FURNACE DOOR FRAME CONSTRUCTION Filed Nov. 24, 1957 2 Shets-Sheei 2 JOHN 7710/? TOM INVENTOR ATTORNEYS Patented Sept. 12, 1939 UNITED STATES PATENT OFFICE 2 Claims.

This invention, as indicated, relates to a furnace door frame construction, more particularly it provides an. improved door frame for furnaces having a destructive degree of heat adjacent the door areas. It is especially adapted for the charging openings of open hearth furnaces. Heretofore passageways have been provided for the insertion of protective layers of fire brick beneath the skew-back supporting the furnace arch to protect the water jacket at the top of the door and the metal of the skew-back. The brick at such position are subjected to extremely severe heat and upon their deterioration must be replaced. With a brick replacement opening such .15 as applicant provides, the renewal of the brick may be readily brought about. The provision of such opening, however, presents a new difficulty in that the walls of the opening become overheated due to improper cooling arrangements. 20 Heretofore the introduction of cooling water to critical areas of the opening walls has been inadequate to produce satisfactory cooling. In the present invention an improved type of structure is provided and ready maintenance of the frame 25 and its associated parts, as well as effective cooling is brought about in such manner as to greatly prolong the service life of the structure.

The principal object of the present invention is to provide a furnace door frame construction hav- 30 ing longer service life and greater protective features against the destructive effect of heat.

Another object of the invention comprises a furnace door frame structure providing for easy renewal of the inner protective wall area.

Another object of the invention is to provide an improved cooling fluid circulation for a furnace door frame structure.

Another object of the invention is to provide a heat dissipating area adjacent certain wall surfaces of the furnace door frame to prevent sagging or distortion of the structure.

Another object of the invention is to provide cooling fluid discharge orifices adjacent critical areas of the wall of the furnace door frame.

A further object of the invention is to provide in a furnace door frame structure protection on its inner side by one or more layers of heat resistant units and having means for replacing such 50 units specially protected against excessive heat effect.

A further object of the invention is to provide a furnace door frame construction having internal wall areas provided with reinforcing and heat 55 radiating fins and having cooling fluid coacting with said fins to prevent deposits of foreign matter on adjacent wall areas.

Other and further objects of the invention will appear in the course of the following description.

The annexed drawings and the following de- 5 scription set forth in detail certain structures embodying the invention, such disclosed means constituting, however, but one of various structural forms in which the principle of the invention may be used. 10

In said annexed drawings:

Figure l is a perspective view of a furnace door frame and the adjacent furnace arch as seen from within the furnace such structure embodying the features of the invention.

Figure 2 is a perspective View of the structure shown in Figure 1 as seen from a position outside of the furnace.

Figure 3 is a fragmentary perspective view showing the skew-back with a double layer of protective fire resistant units beneath the same.

Figure 4 is a fragmentary perspective view showing a portion of the inner passageway of the door frame structure with a single layer of brick or other heat resistant units with a liner of heat dissipating metal adjacent thereto;

Figure 5 is a bottom plan View of the under surface of the lower frame opening wall showing the angularly disposed fluid diverting and heat radiating fins connected thereto;

Figure 6 is a perspective view of a modified form of furnace door frame structure embodying the features of the invention as seen from the outside of the furnace; and

Figure '7 is a View of the structure shown in Figure 6 as seen from within the furnace.

As is clearly shown in the drawings, the fur nace I comprises the usual side walls (not shown) and a roof structure 2, the roof structure being supported upon a channel skew-back 3 having a 40 flange 4 at its lower edge upon which the units forming the roof structure are supported. The furnace door frame is positioned below and in front of said channel skew-back, being supported chiefly by its own weight. The door frame as illustrated comprises two upright side frame members 5, the outer portion 6 of which preferably extends slightly above the lower edge of the skew-back.

This door frame thus provides a charging opening 1 with hollow water cooled side and top walls.

It also may provide water cooled door guides 8 projecting forwardly from the outside face of the door frame.

Over the charging opening 1 the door frame is provided with an elongated horizontal passageway or replacement opening 9 through which brick or the like may be passed to a position immediately beneath the skew-back. This passageway has upper and lower horizontal Walls II and 12, respectively and the under surface of the lower wall l2 may be provided with angularly positioned fins I3 projecting downwardly and tending to cause a somewhat turbulent swirling Water flow over the wall l4 immediately above the charging opening and preventing the deposit of foreign matter at such point.

The fins l3 may be of metal of heat conductive capacity such as copper or aluminum or the like, and liners on one or more of said walls formed of plates 15 or coatings of such metal may be provided as shown in Figure 4.

The door frame structure is preferably hollow throughout and of large cooling fluid capacity. The water or other cooling fluid is preferably admitted at a central point of the structure with a discharge of fluid against the upper inner surface of the wall I l and below the lower inner surface of the wall l2. This may be accomplished with a minimum of obstruction of the passageway 9 through the use of telescopic fluid supply tubes [6, ll, the inner smaller tube crossing the replacement opening 9 at a central point. The fluid will thus be discharged within the frame structure at the points of greatest heat concentration above and below the replacement passageway. It will flow to each side and be discharged through the discharge pipes l8, l9, positioned at the sides with the openings of such pipes preferably spaced slightly from the bottom of the hollow frame structure.

The replacement opening 9 may be made of any desired width and height but as shown in Figs. 1, 2 and 4 is of one brick or of one layer height, and as shown in Fig. 3 is of two brick or two layer height.

The structures shown in Figures 6 and 7 have openings providing for layers of two brick height and have in place of telescopic fluid inlet pipes two lateral inlet pipes 2|, 22 each preferably extending to points immedaitely above the wall above the charging opening. In this manner a very large amount of cooling water will be brought directly against the upper surface of the lower wall 23 of the door frame and prevent sagging or buckling thereof. This is particularly desirable where the cooling chamber above the charging opening is made relatively thin by rea-- son of the space taken up by the double layer of heat resistant brick 24. This cooling fluid flows outwardly through the discharge pipes 25, 26, which preferably extend into closely spaced relation to the bottom.

Other modes of applying the principle of my invention may be employed instead of those explained, change being made as regards the structure herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A furnace door structure comprising a hollow water-cooled frame for a furnace door having a pair of upright members at the sides with outlet pipes extending thereinto, and a transverse member at the upper ends thereof, the body of said frame at its inner portion extending below the channel skew-back with its top wall forming a supporting ledge, and the outer upper portion of the transverse member being of lesser depth and extending slightly above and in front of the channel skew-back, an independent inlet for cooling fluid for the outer upper portion of said member, an open horizontal passageway extending completely through the upper portion of said transverse member closely adjacent said ledge, and cooling means comprising an independent separate inlet for discharging cooling fluid directly against the inner wall surface centrally of the structure, such fluid flowing laterally in each direction from said inlets above and below said passageway and joining as a single fluid flow at the ends thereof adjacent the upper corners of the charging opening and being discharged through said outlet pipes in the pair of upright members.

2. A furnace door structure comprising a 1101- low water-cooled frame for a furnace door having a pair of upright members at the sides with outlet pipes extending thereinto, said members having extensions projecting forwardly from the outside face of the door frame to provide watercooled door guides, and having a transverse memher at the upper ends of said upright members, the body of said frame at its inner portion ex tending below the channel skew-back with its top wall forming a supporting ledge, the outer upper portion of the transverse member being of lesser depth and extending slightly above and in front of the channel skew-back, an open horizontal passageway extending completely through the upper portion of said transverse member closely adjacent said ledge, and cooling means comprising telescopic inlet pipes for independently discharging cooling fluid directly against the inner wall surfaces above and below said horizontal passageway centrally of the structure, such fluid flowing laterally in each direction from said inlets above and below said passageway and joining as a single fluid flow at the ends thereof adjacent the upper corners of the charging opening and being discharged through said outlet pipes in the pair of upright members.

JOHN THORNTON. 

